It is known that when a film is bonded to a substrate such as a liquid crystal cell, the substrate and the film are caught between a pair of rollers opposed to each other (see for example Patent Document 1). A conventional pair of rollers used in the process of bonding an optical film, which typically includes a polarizing plate or the like, to a liquid crystal cell are usually the same in diameter and hardness. The pair of rollers disclosed in Patent Document 1 also have the same geometry.
In some cases, when an optical film is bonded to a liquid crystal cell, a long release film is used as a carrier film, on which the optical film being fed is held. A pressure-sensitive adhesive layer is formed on the optical film, and the release film is attached to the optical film with the pressure-sensitive adhesive layer interposed therebetween. While the release film is peeled off from the optical film being fed, the optical film is bonded to the liquid crystal cell with the pressure-sensitive adhesive layer interposed between, so that a liquid crystal panel is formed.